Intruder mobility in a vibrated granular packing
Laboratoire de Physique et Mécanique des Milieux Hétérogènes (UMR 7636 et Universités Paris 6 et Paris 7) 10 rue Vauquelin, 75005 Paris, France, EU
Accepted: 11 October 2011
We study experimentally the dynamics of dense intruders sinking under gravity inside a vibrated granular packing. The surrounding flow patterns are characterized and the falling trajectories are interpreted in terms of effective friction coefficients related to the intruder's mean descent velocity (flow rules). At higher confining pressures, i.e. close to jamming, a transition to intermittent dynamics is evidenced and displays anomalous “on-off" blockade statistics. A systematic analysis of the flow rules, obtained for different intruder sizes, either in the flowing regime or averaged over the flowing and blockade regimes, strongly suggest the existence of non-local properties for the vibrated packing rheology.
PACS: 45.70.-n – Granular systems / 45.70.Mg – Granular flow: mixing, segregation and stratification
© EPLA, 2011